This characterisation marks the fourth real milestone in Chaney’s distinguished career for with it he was for the first time the undisputed star of a big-budget film and it brought him into close professional association with Irving Thalberg, then working as a production executive for Carl Laemmle at Universal and thus responsible for the best films emerging from MGM. From the beginning, Thalberg had only the highest regard for Chaney’s work, and the Chaney productions he sponsored at Universal and subsequently at MGM were always to reflect faultless taste and careful thought and to provide their star with superlative acting roles… Chaney’s Quasimodo stands as the only one who is emotionally  stirring and truly tragic; his Quasimodo was the ugly beast who adored and protected the beautiful gypsy girl Esmeralda, and although his make-up was grotesque and repulsive, no one could miss the innocent beauty and childlike devotion flooding this unfortunate monster’s heart. His performance was not just an acting tour de force; it was much more than that – a believable interpretation of a very human being.
The ugly hump that disfigured his shoulders and back consisted of 40 pounds of rubber, and he added another 30 pounds of weight to his own with a breastplate and leather harness. When Charles Laughton did his version of Quasimodo for RKO’s Hunchback of Notre Dame, he used a papier-mâché hump that only weighed two pounds for he knew he could never achieve what Chaney had with so excessive a handicap. Said Laughton: “Chaney not only was a great actor; he was a magnificent dancer. The famous ballet stars, like Nijinsky, could express every emotion and every shade of meaning in the movements of their bodies. Chaney had that gift. When he realised that he had lost the girl, his body expressed it – it was as though a bolt of lightning had shattered his physical self. Extraordinary, really!”

DeWitt Bodeen, “Focus on Film”, n. 3, 1970